The 49ers may have come up short in Super Bowl XLVII, but another San Francisco entity came out a big winner Sunday: Twitter.

Various postgame breakdowns on social-media use during Sunday's big event showed Twitter has become the outlet of choice for viewers who increasingly use their mobile phones, tablets, laptops and desktops as secondary screens to multitask while they watch live televised events.

Also, Super Bowl advertisers this year heavily favored posting Twitter hashtags over links to Facebook pages during commercials aired during the game - not an insignificant trend considering that 30-second spots cost up to $4 million each.

"It shows that Twitter has truly established itself as the epicenter of social TV activity and that social activity is on the rise," said Sean Casey, founder of SocialGuide, a social TV measurement and analytics service that is part of NM Incite, a joint venture between ratings service Nielsen and consulting firm McKinsey.

There was almost as much Twitter activity during the Baltimore Ravens' 34-31 victory over the 49ers as there was during all three presidential debates combined, according to NM Incite. The most popular hashtags went with "SuperBowl," "Ravens," "SB47," "49ers" and, not surprisingly, "Beyonce."

Seizing opportunity

"When it comes to second-screen advertising, it's Twitter's world now, and there's no close second place," Matt McGee, editor in chief of industry news site Marketing Land, wrote in a company blog. "Last year, brands split their focus on Twitter and Facebook with eight mentions each. This year, brands recognize that Twitter is where they need to try to attract the online conversation around one of the world's biggest events."

And that included some on-the-spot advertising audibles.

For example, the social-media team employed by cookie maker Oreo, which had already aired a TV spot, moved quickly to take advantage of the 34-minute lull caused by the power failure at the Superdome.

Before the lights came back on, the Oreo team tweeted, "Power outage. No problem," with a link to a cookie photo that read, "You can still dunk in the dark."

That message has been retweeted more than 15,000 times, and the total is closer to 26,000 counting the number of Twitter members who quoted the tweet and added their own comments, according to an analysis by San Francisco's Salesforce.com.

Meanwhile, apparel maker Calvin Klein, which was already trending on Twitter after titillating audiences with a spot featuring a sexy male model wearing its underwear, used Twitter's new Vine video service to tweet a short clip of a man working on his already well-formed six-pack abs.

The place to go

Overall, Salesforce said Twitter was the social platform of choice for those using second screens. Altogether, it said, there were more than 25 million game-related social-media posts across various platforms, including Twitter, Facebook, YouTube, LinkedIn, blogs and forums.

The number peaked at 5 million in the hour after the game, which by itself came close to the total of 6.6 million posts that Salesforce recorded during all of last year's Super Bowl.

Salesforce's numbers may appear confusing,considering that Twitter itself said it counted 24.1 million game-related tweets, surpassing its total from the 2012 game by the start of the second half. And that did not include tweets about TV commercials.

But Salesforce's numbers measured only publicly available posts, which would exclude private Twitter posts and many Facebook posts that members set to be viewed only by networks of "friends" or "friends of friends."

Facebook did say the Super Bowl generated the second-largest volume of posts in one day this year, just behind New Year's Day, but the Menlo Park company did not divulge specifics. It did offer one number: Niners head coach Jim Harbaugh received 98 percent more mentions than his brother, Ravens head coach John Harbaugh.

Twitter said the heaviest volume of tweets was about non-football events - Beyoncé's halftime extravaganza, which included an on-stage reunion with her former Destiny's Child mates that generated a peak 257,500 tweets per minute - and the power outage.

Retiring Ravens linebacker Ray Lewis was also a popular subject, both on Twitter and Facebook.

Advertisers jump in

Advertisers did more this year to inject themselves into the social conversations.

Analyst Jeremiah Owyang of San Mateo consulting firm Altimeter Group said he even expects advertisers to use Twitter hashtags more than company websites in commercials during next year's Super Bowl.

He said 75 percent of the commercials broadcast during the game mentioned a link to a second-screen experience, a 7 percent increase from last year.

Of those, 46 percent included a corporate website, down 8 percent from the prior year, while 11 percent included a Facebook page, down 4 percent from the year before. Google's social network, Google+, was not mentioned at all.

But the use of Twitter hashtags jumped from 7 percent to 38 percent, Owyang said.

Hashtags are turning out to be popular because they can be used on a variety of social networks, even Facebook, he said.

But Twitter's big Super Bowl victory doesn't necessarily mean the microblogging service will be as dominant outside of major, live televised events.

"Twitter will continue to be dominant in real-time events, as it spurs on fast, real-time interaction from mobile devices," Owyang said. "Facebook offers more engagement features, which can have a long-lasting relationship with viewers days and weeks after the event."